Instrument Availability and Target Accessibility: 2007A

Instrument Availability and Target Accessibility: 2007A

This page provides best estimates, at the time of the Call for Proposals, of instrument availability and corresponding
target (RA, dec) restrictions for 2007A.

General

Instrument Changes: As there are more instruments than the number of available ports on each
telescope, instrument swaps will be required. Therefore not all instruments will be available for the entire semester.
However, whenever possible instrument swaps will be scheduled to
minimize impact on the queue, that is, instrument swaps will be driven
by demand as much as possible and so the final schedule will not be
made until after the 2007A programs are known. Never the less, it
may be the case that certain targets or entire programs will not be
feasible once the final schedule is determined, at ITAC or thereafter. This is
especially true at Gemini South, where a significant fraction of the
schedule is reserved for new instrument commissioning.

No instrument changes are permitted during classical runs.

Under-utilized instruments: Community demand is a critical
factor in determining instrument availability. Gemini maintains
as a "minimum goal" that any instrument must be
awarded at least 160 hours (approx 16 nights) in order to be mounted on
the telescope. In
semesters 2006A and 2006B the
following instruments only barely or did not meet the 16-night minimum
criterion: MICHELLE, T-ReCS, bHROS. As each instrument introduces
significant overhead to the Observatory, and access to instrument ports
is at a premium, Gemini reserves the right to withdraw support for any
instrument for which this under-utilization condition persists.

Gemini North

At Gemini North, NIFS and Michelle share the up-looking port.
It is expected that
Michelle will be mounted at the start of the semester, NIFS will occupy
the middle of the semester and Michelle will be re-mounted near the
end. The exact dates of these swaps will be driven largely by
consideration of the targets in the queue. Therefore, there are
no special target restrictions on any Gemini North instruments in 2007A.

However, observations requiring the Laser Guide Star (LGS) system
are restricted by the limitation that the LGS must be used at or above
49 degrees elevation. How this translates into RA and dec
restrictions is indicated in the figure below.

In addition, because of the requirement to obtain advance approval of all telescope
pointings, it is not possible to use LGS with Rapid Response Target of Opportunity observations.
Standard ToO LGS observations may be possible in the future if targets can be defined well in advance but
are not being considered for 2007A.

The following figure displays the accessibility of targets as a
function of RA (horizontal axis) and Declination (vertical axis) at
Gemini North for the 2007A semester. The dark gray area indicates
the restriction on LGS observations. The larger light gray area
indicates sky positions that are above 2.5 airmasses for at least 2
hours on at least 7 days of the semester. Targets outside this
area should not be requested in 2007A. However, these represent
the minimum criteria for
scheduling an observation in the queue (or classically), and proposers
with targets very close to the extremes are advised to consider
carefully other factors such as the amount of time needed on the
source, the observing conditions required and the likely weather at the
time (early in the semester is more likely to have poor weather on
Mauna Kea), and the maximum airmass acceptable for the observation.

Figure 1: Target accessibility at Gemini North during semester 2007A.

Gemini South

At Gemini South, 30% of the semester is reserved for engineering,
including new instrument commissioning (both NICI and Flamingos-2) and
the start of multi-conjugate adaptive optics (MCAO)
commissioning. NICI will share the up-looking port with T-ReCS
and
Flamingos-2 will share a side port with GMOS-S. The start of MCAO
engineering will displace Phoenix, which is currently located on the
"AO" port. At this writing, it is expected that NICI will occupy
the up-looking
port at the start of the semester, followed by T-ReCS for the remainder
of the semester. GMOS-S is expected to be dis-mounted late in the
first half of
the semester for Flamingos-2 commissioning and then re-mounted near the
end of
the semester. bHROS is not available when GMOS-S is off the
telescope. However, given the uncertainty of new instrument
commissioning schedules, no special target restrictions are being
placed on T-ReCS, GMOS-S, bHROS or GNIRS in 2007A.

However, it is reasonably certain that Phoenix will be removed from
the telescope after March 2007. Hence, Phoenix targets are
restricted to February-March, as indicated in the figure below.

The following figure displays the accessibility
of targets as a function of RA (horizontal axis) and Declination
(vertical axis) at Gemini South for the 2007A semester. The dark
gray area indicates the restriction on Phoenix observations. The
larger light gray area indicates sky positions accessible at some time
during the semester. Targets outside this area should not be
requested in 2007A. In both cases, accessibility is defined as
positions above airmass 2.5 for at least 2 hours on at least 7 days
during the semester (or during February-March in the case of
Phoenix). However, these represent the minimum criteria for scheduling an observation in the
queue (or classically), and proposers with targets very close to the
extremes are advised to consider carefully other factors such as the
amount of time needed on the source, the observing conditions required
and the likely weather at the time (late in the semester is more
likely to have poor weather on Cerro Pachon), and the maximum airmass
acceptable for the observation.